1. Field of the Invention
This invention relates to reusable, releasable, tamper resistant fasteners which are removably attachable to shafts, such as shafts of pin members, and which are designed to be nondestructably releasable from the pin member only upon the use of a special tool and more particularly relates to reusable, releasable, tamper resistant fasteners for use in connection with monitor actuating devices for removable attachment to the shank of a pin member to attach a monitored article to a monitor actuating device and for nondestructive removal from the pin shank upon the use of a special tool.
2. Description of the Prior Art
Reusable releasable fasteners for selective attachment to the free end of shanks of pin members or the like for use in connection with monitor actuating devices, such as are commonly used in anti-theft systems, to capture a monitored article on the shank of the pin member between the head of the pin and the removable fastener and for resisting nondestructive removal from the pin shank except upon the use of a special tool are well known in the prior art and examples thereof may be seen by reference to U.S. Pat. Nos. 3,911,534; 3,914,829; 3,932,918; 4,000,543 and 4,104,622, all of which are hereby incorporated by reference. In general, these prior art devices were effective to be firmly retained on the shank of a pin and to resist nondestructive removal from the shank of the pin except by use of a specialized tool which might be magnetic, heat and/or mechanical in nature. While the prior art devices have proven effective in many circumstances, certain of the prior art devices were not suitable for all purposes as they were difficult to remove, complicated and/or expensive to manufacture. The use of certain of the prior art devices was not considered satisfactory in certain situations as it was desirable to provide selectively removable fasteners which operated on a different principal and utilized a different type of removal tool than other existing selectively removable fasteners to create a situation making unauthorized removal of the fasteners by amateur shoplifters, who are believed to represent the greatest source of shoplifting losses, more difficult.